That's the point I don't understand. slapd works w/o any problems for
two or three weeks and then 'boing', suddenly cannot 'communicate'
with the underlying bdb.

IIRC, RedHat also links 2.2.13 against BDB 4.3.21, which was a horribly
broken BDB release, but I may be incorrect in that. I personally recommend
against using the OpenLDAP provided by RedHat for running directory server,
instead either building your own setup (including BDB 4.2.52 + patches) or
downloading free, RPM based precompiled versions like CDS from
http://www.symas.com/